Compositions that can effectively moisturize and protect the skin during the bathing process while the skin is still wet are a potentially convenient, and time saving approach to skin treatment. By bathing is meant any number of processes commonly used to cleanse the body and face, e.g., showering. To be truly effective, these compositions must be such that an adequate level of benefit agent is retained on the skin after rinsing and/or towel drying without at the same time imparting an excessively oily feel to the wet and dry skin and without leaving it looking too shiny.
Bath oil which is used by some consumers, must be applied sparingly because it does not absorb efficiently on the skin and the excess can be very oily and messy. Furthermore light bath oils (i.e., oils that have a low viscosity and spread on the skin) absorb more rapidly to overcome this problem are not very effective in providing longer lasting benefits.
Conventional oil-in-water emulsion type skin lotions or creams that are designed to be applied to dry skin, even water resistant variants, are very poorly retained when applied to wet skin that is either further rinsed or towel dried. By contrast, conventional water-in-oil skin lotions that are designed for application to dry skin are very efficiently retained on wet skin but are excessively greasy and messy and are not perceived to absorb quickly.
U.S. Pat. No. 5,578,299 to Starch and U.S. Pat. No. 5,928,632 are directed to gelled mineral oil compositions wherein the mineral oil is gelled by a specific oil soluble copolymers (ethylene/propylene/styrene/ and butylene/ethylene/styrene). No mention is made of structured oils wherein the structurant forms a network of finely divided solids, nor the criticality of the rheological properties of such networks, or of the droplet size. There is certainly no process for making such compositions disclosed.
Further, the compositions described in U.S. Pat. No. 5,578,299 to Starch and U.S. Pat. No. 5,928,632 although they deposit on skin, are still perceived as greasy.
U.S. Pat. No. 5,661,189 to Grieveson et al is directed to an aqueous cleansing and moisturizing composition containing a dispersion of a thickened benefit agent. No mention is made of the criticality that the composition should have a mildness index as measured by the zein solubility test below a specific value (essentially equal to water). Furthermore, there is no mention that the compositions of U.S. Pat. No. 5,661,189 must have a foam generation index below a critical value as measured by the shake test (essentially non-foaming), and no mention that the thickening agents must be limited to structurants that specifically form a network of finely divided solids having the properties defined herein.
Finally, in copending U.S. Ser. No. 09/796,150 entitled “Process for Making Mild Moisturizing Liquids Containing Large Oil Droplet”, applicants disclose a process for making large oil droplets using screens. This application, however, is specific to compositions containing surfactant (5 to 35% surfactant) and further does not relate to an oil structured by finely divided solids.
Thus, there remains a need for compositions and process of making such compositions that can be applied to wet skin, absorb quickly and are perceived to be effective skin treatments and provide natural looking and natural feeling skin.
One objective of the current invention is to provide a process of making composition in which the benefit agent efficiently deposits on wet-skin and is retained to a high degree when the skin is subsequently rinsed and dried.
A further objective is to provide a process of making a composition in which the oil phase is perceived to rapidly absorb when the composition is applied and rubbed on the wet skin.
A further objective is to provide a process of making a composition that is perceived to moisturize and protect the skin while still being perceived to leave the skin clean and with a natural look and a moisturized feel.
A still further objective of the present invention is to provide a convenient method to moisturize and treat the skin to yield an enduring effect that can be accomplished conveniently and routinely in a single step as part of the bathing process. Such a process will obviate the need for separate treatments.
Applicants have found that these and other objectives can be realized through the use of oil-in-water compositions in which the oil phase is specifically structured through a network comprising finely divided solid particle and the structured phase and the composition posses specific functional properties according to the tests described herein.